Australia tax agent client onboarding checklist 2026

Before 31 October 2026#

1. Confirm authority to act

   Notify the ATO through Online services for agents so the client appears on your client list.

2. Check prior years

   Find any overdue returns and lodge them by 31 October 2026.

3. Check how the client lodged before

   A client who previously prepared their own return is not covered by your program and may face an earlier due date.

4. Confirm the due date on the client list

   Use the date the client list shows; the ATO can ask for a return earlier than the program date.

What to collect for the 2025–26 return#

• Income statements and any income not on them (interest, dividends, rent, foreign income, business income).
• Records for every deduction claimed, kept for five years.
• Private health insurance and Medicare levy details.
• Prior-year notices of assessment and any amendment requests.

What the reviewer checks#

• The client is on the client list, with the program due date recorded.
• Every figure traced to an income statement or a record.
• Anything unusual flagged with the reason, before lodgment.

What this rests on

1. 1Registered agent lodgment program 2026–27 — Due dates by month — October 2026Australian Taxation Officein force from 1 July 2026
2. 2Ensure clients are covered by your lodgment program — Notify us of your authority to actAustralian Taxation Officein force from 1 July 2026

Locators, not document titles. A citation naming the act without naming the section is not one anybody can check.

Where this fits

• The filing calendarWhere filing deadlines is covered in depth
• Coverage for AustraliaIts disclosed limitation: State and territory sub-regions modelled where data exists.
• Canada corporate year-end tax checklist 2026The same topic in CA
• UK MTD quarterly update review checklist 2026The same topic in UK
• US tax filing deadlines (IRS)The same topic in US

Related guides, and why

• Guide

  Canada corporate year-end tax checklist 2026

  What to gather and check before a T2 return for a 2026 year-end: the filing date, the balance-due date, and the documents a reviewer needs to sign off.

  Also about filing-deadlines

• Guide

  UK MTD quarterly update review checklist 2026

  Who must use Making Tax Digital for Income Tax from April 2026, the quarterly update deadlines, and what to check before each update is sent.

  Also about filing-deadlines

• Guide

  US tax filing deadlines (IRS)

  The dates that matter for a federal individual return, what an extension actually extends, and the distinction that costs people money — filing late and paying late are two different penalties.

  Also about filing-deadlines